diff --git a/Project/Sprint2/app/src/androidTest/java/com/example/sprint1/ExampleInstrumentedTest.java b/Project/Sprint2/app/src/androidTest/java/com/example/sprint1/ExampleInstrumentedTest.java
index 56faba6..2ce5c2a 100644
--- a/Project/Sprint2/app/src/androidTest/java/com/example/sprint1/ExampleInstrumentedTest.java
+++ b/Project/Sprint2/app/src/androidTest/java/com/example/sprint1/ExampleInstrumentedTest.java
@@ -1,26 +1,156 @@
 package com.example.sprint1;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
 import android.content.Context;
 
-import androidx.test.platform.app.InstrumentationRegistry;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.platform.app.InstrumentationRegistry;
 
+import com.example.sprint1.viewmodel.MainViewModel;
+
+import org.junit.Assert;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
-import static org.junit.Assert.*;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
 
-/**
- * Instrumented test, which will execute on an Android device.
- *
- * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
- */
 @RunWith(AndroidJUnit4.class)
 public class ExampleInstrumentedTest {
+    private static final MainViewModel mainViewModel = new MainViewModel();
+
     @Test
     public void useAppContext() {
-        // Context of the app under test.
         Context appContext = InstrumentationRegistry.getInstrumentation().getTargetContext();
         assertEquals("com.example.sprint1", appContext.getPackageName());
     }
+
+    @Test
+    public void testUserSignUpWithExistingUsername() {
+        mainViewModel.userSignUp("testUser", "testPassword", Assert::assertFalse);
+    }
+
+    @Test
+    public void testUserSignInWithCorrectCredentials() {
+        mainViewModel.userSignIn("tianrui", "1", Assert::assertTrue);
+    }
+
+    @Test
+    public void testUserSignInWithIncorrectPassword() {
+        mainViewModel.userSignIn("tianrui", "2", Assert::assertFalse);
+    }
+
+    @Test
+    public void testAddDestinationWithValidData() {
+        mainViewModel.userSignIn("testUser", "testPassword", Assert::assertTrue);
+        mainViewModel.addDestination("Paris", "01/01/2023", "01/11/2023", Assert::assertTrue);
+    }
+
+    @Test
+    public void testAddDestinationWithAdditionalValidData() {
+        mainViewModel.userSignIn("testUser", "testPassword", Assert::assertTrue);
+        mainViewModel.addDestination("New York", "01/04/2023", "01/06/2023", Assert::assertTrue);
+    }
+
+    @Test
+    public void testAddDestinationWithDuplicateLocation() {
+        mainViewModel.userSignIn("testUser", "testPassword", Assert::assertTrue);
+        mainViewModel.addDestination("Atlanta", "01/01/2023", "01/11/2023", Assert::assertTrue);
+    }
+
+    @Test
+    public void testGetDestinationsWithExistingDestinations() {
+        mainViewModel.userSignIn("testUser", "testPassword", Assert::assertTrue);
+        mainViewModel.getDestinations(result -> assertTrue(result.containsKey("Paris")));
+    }
+
+    @Test
+    public void testGetDestinationsWithNoDestinations() {
+        mainViewModel.userSignIn("testUser", "testPassword", Assert::assertTrue);
+        mainViewModel.getDestinations(Assert::assertNull);
+    }
+
+    @Test
+    public void testSetVacationWithValidDatesAndDuration() {
+        mainViewModel.userSignIn("testUser", "testPassword", Assert::assertTrue);
+        mainViewModel.setVacation("01/01/2023", "01/10/2023", "10", Assert::assertTrue);
+        mainViewModel.getVacation(result -> {
+            assertEquals("01/01/2023", result.get("startDate"));
+            assertEquals("01/10/2023", result.get("endDate"));
+            assertEquals("10", result.get("duration"));
+        });
+    }
+
+    @Test
+    public void testSetVacationWithMismatchedDuration() {
+        mainViewModel.userSignIn("testUser", "testPassword", Assert::assertTrue);
+        mainViewModel.setVacation("01/10/2023", "01/01/2023", "5", Assert::assertFalse);
+    }
+
+    @Test
+    public void testCalculateOccupiedDaysWithValidVacationAndDestinations() {
+        mainViewModel.userSignIn("testUser", "testPassword", Assert::assertTrue);
+        mainViewModel.setVacation("01/01/2023", "01/21/2023", "21", Assert::assertTrue);
+        mainViewModel.addDestination("Paris", "01/01/2023", "01/11/2023", Assert::assertTrue);
+    }
+
+    @Test
+    public void testCalculateOccupiedDaysWithNoOverlap() throws InterruptedException {
+        CountDownLatch latch = new CountDownLatch(1);
+        mainViewModel.userSignIn("testUser", "testPassword", result -> {
+            assertTrue(result);
+            latch.countDown();
+        });
+        assertTrue(latch.await(5, TimeUnit.SECONDS));
+
+        mainViewModel.setVacation("01/01/2023", "01/30/2023", "30", Assert::assertTrue);
+        mainViewModel.addDestination("Paris", "01/15/2023", "01/20/2023", Assert::assertTrue);
+    }
+
+    @Test
+    public void testLogTravelWithEmptyLocation() {
+        mainViewModel.addDestination("", "01/01/2023", "01/10/2023", Assert::assertFalse);
+    }
+
+    @Test
+    public void testLogTravelEntryStoredInDatabase() {
+        mainViewModel.userSignIn("testUser", "testPassword", Assert::assertTrue);
+        mainViewModel.getDestinations(result -> {
+            assertNotNull(result);
+            assertTrue(result.containsKey("TestLocation"));
+        });
+    }
+
+    @Test
+    public void testAccountCreationWithWhitespaceOnlyInput() {
+        mainViewModel.userSignUp("   ", "validPassword", Assert::assertFalse);
+    }
+
+    @Test
+    public void testAccountCreationWithNullInput() {
+        mainViewModel.userSignUp(null, "validPassword", Assert::assertFalse);
+    }
+
+    @Test
+    public void testAccountCreationWithEmptyStringInput() {
+        mainViewModel.userSignUp("", "validPassword", Assert::assertFalse);
+    }
+
+    @Test
+    public void testAccountLoginWithWhitespaceOnlyInput() {
+        mainViewModel.userSignIn("   ", "validPassword", Assert::assertFalse);
+    }
+
+    @Test
+    public void testAccountLoginWithNullInput() {
+        mainViewModel.userSignIn(null, "validPassword", Assert::assertFalse);
+    }
+
+    @Test
+    public void testAccountLoginWithEmptyStringInput() {
+        mainViewModel.userSignIn("", "validPassword", Assert::assertFalse);
+    }
 }
\ No newline at end of file
diff --git a/Project/Sprint2/app/src/main/java/com/example/sprint1/view/HomeDes.java b/Project/Sprint2/app/src/main/java/com/example/sprint1/view/HomeDes.java
index 5d6400b..833aa5e 100644
--- a/Project/Sprint2/app/src/main/java/com/example/sprint1/view/HomeDes.java
+++ b/Project/Sprint2/app/src/main/java/com/example/sprint1/view/HomeDes.java
@@ -115,23 +115,23 @@ private void formCalculate() {
                                 startDate.setText("");
                                 endDate.setText("");
                                 duration.setText("");
-                                mainViewModel.calVacation(
-                                        occupiedDays -> {
-                                            // Update the result view with the occupied days
-                                            if (occupiedDays != null) {
-                                                resultView.setText(getString(
-                                                        R.string.HomeDestination_Calculate_Message, occupiedDays
-                                                ));
-                                            } else {
-                                                resultView.setText(R.string.HomeDestination_Calculate_Error);
-                                            }
-                                        }
-                                );
+                                mainViewModel.calVacation(occupiedDays -> {
+                                    // Update the result view with the occupied days
+                                    if (occupiedDays != null) {
+                                        resultView.setText(getString(
+                                                R.string.HomeDestination_Calculate_Message,
+                                                occupiedDays
+                                        ));
+                                    } else {
+                                        resultView.setText(
+                                                R.string.HomeDestination_Calculate_Error
+                                        );
+                                    }
+                                });
                                 formCalculate.setVisibility(View.GONE);
                                 resultCalculate.setVisibility(View.VISIBLE);
                             }
-                        }
-                )
+                        })
         );
     }